I. Field of the Invention
The present invention relates to a modular intramedullary nail system for the repair of long bone fractures which provides for a large number of resulting nail sizes from a relatively small number of base nails and extension members.
II. Description of the Prior Art
The concept of using various fastening devices for rejoining bones which have become fractured is well known. For example, U.S. Pat. No. 4,467,794 discloses an assembly which comprises a pair of tubular members adapted to be inserted in the intramedullary passages of the respective parts of a broken bone. U.S. Pat. No. 3,530,854 discloses a telescoping nail assembly which is of particular value in repairing fractures in the femoral head. Similar bone screw devices are also disclosed in U.S. Pat. Nos. 4,530,355, and 4,640,271.
It is noteworthy, however, that in none of the prior patents just cited, is there provision of any structure which prevents relative movement, either rotationally or longitudinally, between the components of the fastener system.
Although the foregoing devices satisfy the goals for which they each intended, none specifically addressed the problem of providing a modular intramedullary nail system by reason of which a relatively small number of inventoried components would satisfy virtually all requirements within a hospital setting. It was with knowledge of the prior art and of the situation then existing that the present invention has been conceived and reduced to practice.